VulnerabilityPublished 6 May 2024Updated 2 Aug 2024

CVE-2024-34251: wasm-micro-runtime · Out-of-bounds Read

Affects wasm-micro-runtimeSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubbytecodealliance/wasm-micro-runtime`pkg:github/bytecodealliance/wasm-micro-runtime`Other threats	Affected =2.0.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-34251, organizations should first inventory and identify all deployments of Bytecode Alliance wasm-micro-runtime version 2.0.0 or earlier. Until an official patch is released, restrict network access to services running the vulnerable runtime to trusted sources only, minimizing exposure to remote attackers. Employ runtime memory protection techniques such as AddressSanitizer or similar tools during development and testing to detect and prevent out-of-bound memory accesses. Implement input validation and sandboxing to limit the processing of untrusted or malformed WebAssembly modules. Monitor system logs and application behavior for crashes or anomalies indicative of exploitation attempts. Engage with the Bytecode Alliance and related open-source communities to track patch releases and apply updates promptly once available. Consider deploying WebAssembly runtimes with built-in memory safety features or alternative implementations if immediate patching is not feasible. Additionally, incorporate WebAssembly security best practices, including strict module validation and limiting runtime privileges. Establish incident response plans to quickly address potential denial of service events related to this vulnerability.

Description

An out-of-bound memory read vulnerability was discovered in Bytecode Alliance wasm-micro-runtime v2.0.0 which allows a remote attacker to cause a denial of service via the "block_type_get_arity" function in core/iwasm/interpreter/wasm.h.

Impact

The primary impact of CVE-2024-34251 is the potential for remote denial of service attacks against systems running vulnerable versions of wasm-micro-runtime. This can disrupt services that rely on WebAssembly execution, causing application crashes and downtime. Organizations embedding wasm-micro-runtime in cloud services, edge computing devices, IoT platforms, or embedded systems may experience service interruptions, affecting availability and operational continuity. Although the vulnerability does not compromise confidentiality or integrity, the loss of availability can have cascading effects, especially in critical infrastructure or high-availability environments. Attackers can exploit this vulnerability remotely without authentication or user interaction, increasing the risk of widespread disruption. The absence of known exploits in the wild currently limits immediate risk, but the public disclosure may prompt attackers to develop exploits. The impact is magnified in environments where wasm-micro-runtime is exposed to untrusted inputs or network access, such as multi-tenant cloud platforms or public-facing services. Organizations relying on this runtime for secure code execution should consider the risk of service degradation or denial of service as a significant operational threat.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/bytecodealliance/wasm-micro-runtime/issues/3347 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 04:41 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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